Publication EP 1229509 discloses a laminate including duplex labels laminated together by patches of adhesive alternating oppositely therebetween. The labels may be removed from each other, with each label having adhesive on the back side thereof. When an adhesive patch is intended to be on the surface of the first label then there is a silicone release layer between the adhesive patch and the surface of the second label.
Publication WO 97/03839 discloses a method and an apparatus for hot-melt printing. The invention can be utilized e.g. for delivering adhesive patterns to a web material. One example is a zone coated label stock.
A problem related to patch-like adhesive patterns is that opposite to the patch there must be a patch-like release layer, which makes the manufacturing process complicated. It is also desirable to get rid of silicone release agents because-of-their high price. On the other hand, the use of the release agents has been compulsory because otherwise there is no possibility to release different layers from each other. A presence of the silicone release agent is detected for example by a surface energy measurement and the obtained value is between 20 and 22 dynes.